1. Field of the Invention
The present invention relates to a cushion for use for assisting a user in doing various types of stretching exercises, in particular, to a stretch assisting cushion suitable for use for assisting a user in doing stretching exercise for user's body portion including hip joints.
2. Description of the Related Arts
Currently, it is widely popularized to exercise various types of stretches at sports clubs, at training gyms, or at home according to the health-conscious boom. Among the various types of the stretches, in particular, leg-split type stretching exercises are widely done to stretch person's body portion including hip joints by splitting person's legs because those exercises are suitable for reinforcing the body portion around their joints and are effective for antiaging.
In cases where these leg-split type stretching exercises are done on the floor of the house or on a conventional flat mat/cushion, no appropriate stretching exercise for stretching person's body portion including hip joints can be done because a person's pelvis tends to be inclined rearward and a person's spine is forced to be bent due to an excess stress on the back. This causes a serious problem for, in particular, a person who has a stiff body and an aged person.
Meanwhile, there has been known a simple device for correcting sitting position of lumbar (hereinafter, it will be abbreviated to “lumbar position correction device”) (for example, see Japanese Paten Laid-Open Publication 2000-79135) that may be mounted on a sitting surface of a chair and may keep user's pelvis to be inclined forward by correcting sitting position of user's lumbar. To address the above-mentioned problem in which the pelvis tends to be inclined rearward while doing the leg-split type stretching exercises, it will be considered to use the lumbar position correction device, the device being disclosed in Japanese Paten Laid-Open Publication 2000-79135, to keep the pelvis to be inclined forward while doing the stretching exercises.
The lumbar position correction device according to the description of Japanese Paten Laid-Open Publication 2000-79135 includes a main body which is formed in substantially bar-shaped and has a wedge-shaped cross section so that a tilted surface is appeared when the lumbar position correction device is located on the sitting surface of a chair. Thus, when a user sets on the tilted surface of the device located on the sitting surface of the chair, the tilted surface helps user's pelvis to be inclined forward depending on a tilted angle of the surface. However, when the user does leg-split type stretching exercises while this device is located directly on the floor, it is considered that the user cannot do leg-split type stretching exercises appropriately due to the reason mentioned below.
For example, when the lumbar position correction device according to the description of Japanese Paten Laid-Open Publication 2000-79135 is located on the floor and the leg-split type stretching exercises are done, there is only a small distance between the sitting surface formed by the tilted surface of the device and the floor, in particular, an edge line of the tilted surface of the device is substantially the same level as the floor so that it is hard for users to incline their pelvises forward deeply. Accordingly, it is difficult to do appropriate and effective leg-split type stretching exercises.
To secure a necessary level of the sitting surface formed by the tilted surface of the device from the floor, it can be considered that the user does stretching exercises using this lumbar position correction device while the device is mounted on a flat surface of a stretch mat/cushion. However, because the stretch mat/cushion sandwiched between the floor and the device would in general be soft, the sitting surface will incline and become unstable, and thereby making it hard to maintain the tilted angle of the tilted surface of the device such that the users can incline their pelvises forward deeply. Further, the lumbar position correction device may be displaced relative to the stretch mat/cushion located below the device while the user does the stretching exercises using the device so that it becomes difficult to continue the stretching exercises.